Bulk single crystals of aluminum nitride

Abstract

Bulk, low impurity aluminum nitride (AlN) single crystals are grown by sublimation or similar deposition techniques at growth rates greater than 0.5 mm/hr.

What is claimed is:  
     
       1. A bulk single crystal of AlN grown by deposition of vapor species containing Al and N on a seed crystal growth surface, said bulk single crystal having a sufficient size and sufficient purity to permit its use in electronic applications, with the crystal having a diameter greater than about one inch and the purity of the crystal being characterized by the crystal lattice structure thereof having a level of nonintentionally introduced impurities below about 450 ppm. 
     
     
       2. The crystal of claim  1  wherein the level of nonintentionally introduced electrically active impurities is below about 75 ppm. 
     
     
       3. The bulk single crystal of claim  1 , further comprising an epitaxial layer of AlN deposited thereon. 
     
     
       4. The bulk single crystal of claim  1 , wherein a surface of said crystal is processed to be receptive to the deposition of a thin film of AlN. 
     
     
       5. The bulk single crystal of claim  3 , wherein said epitaxial layer is formed by a process selected from the group consisting of MBE, MOCVD and nitrogen plasma sputtering. 
     
     
       6. The bulk single crystal of claim  3 , wherein said epitaxial layer has a thickness of 1.5 to 2 microns. 
     
     
       7. The bulk single crystal of claim  3 , wherein said epitaxial layer is doped with a dopant. 
     
     
       8. The bulk single crystal of claim  4 , wherein said surface is processed by dry etching. 
     
     
       9. A bulk single crystal of intentionally doped n-type or p-type AlN grown by deposition of vapor species containing Al and N on a seed crystal growth surface in the presence of doping atoms, said bulk single crystal of AlN having an electrical resistivity below 0.30 ohms-cm and a diameter greater than one inch. 
     
     
       10. A bulk single crystal of intentionally doped n-type or p-type AlN grown by deposition of vapor species containing Al and N on a seed crystal growth surface in the presence of doping atoms, said bulk single crystal of AlN being compensated by the doping thereof and having a diameter greater than one inch.